The Meso-and Macroporous Nanosized Catalyst Supports For Residual Hydrotreating Processes

Great improvement in petroleum processing technology has been depending on the new achievements in modern catalytic material science. The investigation on nanostructurally catalytic materials with meso-and macroporous structures has promoted the development of new generation catalyst for residual hydrotreating processes. In this dissertation, the nanostructural materials of γ-Al2O3and SiO2-Al2O3with meso-and macroporous structures were synthesized within supersoluble reverse micelles as uniform micro-reactors under the same operational conditions. Furthermore, the new residual hydrotreating catalysts were prepared by distributing impregnation into secondary assemblies of γ-Al2O3and SiO2-Al2O3rod nanoparticles. Subsequently, the residual hydrogenation catalysts were evaluated on small scale test unit and industrial plant to examine the performances on residue hydrodemetallization (HDM), hydrodesulfurization (HDS) as well as catalyst grading loading technology. In addition, the spent HDM catalysts were in the deposition content and radial distribution of the removed transition metal.The nano-sized γ-Al2O3materials with meso-and macroporous structures were prepared by supersoluble secondary self-assembly synthesis after an examination in calcination temperature, template and adhesive contents, and molding methods. The synthesized materials were characterized by XRD, TG-DSC, TEM, SEM, and both of N2adsorption and mercury intrusion methods. The γ-Al2O3supports show extraordinary pore structural properties, such as high specific pore volume (1.011-2.715cm3·g-’), specific surface area (188.0-411.4m2·g-’), mean pore diameter (12.0-57.7nm) with the large pore volume rate of pore size larger than10nm, large porosity (69.0-96.0%) as well as high mechanical strength (15.97-20.76N·mm-2). The nano-sized SiO2-Al2O3rod supports with meso-and macroporous structures were prepared under suitable conditions in calcination temperature, doped SiO2and template contents. The opening frameworks of the rod supports were confirmed by TEM, SEM and N2adsorption, along with remarkable meso-and macroporous structures. rod supports were provided with a high ratio of Lewis acid site to Bronsted acid site upon NH3-TPD and pyridine-adsorbed IR.Co-Mo/SiO2-Al2O3(FAS-47) and Ni-Mo/y-Al2O3(FA-C7) catalysts were prepared by distributing immersion method. The catalyst FAS-47exhibits prominent structure properties, viz. high specific surface area, porous volume and factor of porosity. The main pore diameter measured is about12.0nm by BET method and distribution of pore size in range of10-100nm arrives at71.21%by mercury intrusion method. Furthermore, the FAS-47catalyst maintains the inherent opening skeleton structure of the employed SiO2-Al2O3supports. For FA-C7catalyst, the most probable pore diameter seems to be reduced but shows the high specific surface area and the larger pore volume by mercury intrusion method compared with FAS-47catalyst. The Ni-Mo active components as metal oxide clusters are more homogeneously dispersed on the γ-Al2O3support where this Ni-Mo dispersed state can generate synergic catalytic centers after sulfuration. Otherwise, the molding FA-C7catalyst reveals not only a larger porous structure and but also a higher mechanical strength.FAS-47catalyst was evaluated over a200mL fixed bed continuous flow reaction unit using Saudi Arabia light residue. FAS-47catalyst shows an excellent hydrodesulfurization performance. On the other hand, the FA-C7and FAS-47catalysts have been running for3000h, respectively on a demonstration unit in industrial scale in comparison with the commercial referred catalysts. FAS-47as a HDS catalyst has been confirmed slightly superior to foreign commercial referred catalyst. The metal removal activity of the combined catalysts has been significantly increased by replacing domestic HDM catalyst with FA-C7while FA-C7can improve the HDS performance of new combination catalysts. Fe, Ni and V components feature different radial deposit and distribution in the inactive FA-C7catalyst particles obtained by distributing immersion method. Fe, Ni and V components in the inactive FA-C7catalyst particles take on deposit and radial distribution features. In fact, Fe, Ni deposition contents are always lower but V content keeps higher level on the exterior surface of inactive FA-C7particles. However, with a radial deepening, Fe content tends to deposit on the granule center region and the Ni and V contents show maxima at around480μm and500μm, respectively. In general, FA-C7metal deposits reach interior surface and the metal capacities excel commercial HDM catalysts.